Cartridges (also known as rounds) for firearms are elongated. A typical cartridge includes a shell casing, made of brass, which is filled with an explosive propellant. At its rear or closed end, the casing has a rim or flange containing a primer. Next to the rim is an extractor groove, an annular groove machined into the casing which provides a grip for the gun's extractor to pull the fired or unfired casing from the chamber of the firearm. The front and opposite end of the casing is open. A bullet, projectile, or head, usually of lead (optionally jacketed) is partially inserted into the open or front end of the case by crimping the casing onto the bullet.
Some rifles have internally fixed magazines for feeding cartridges into a chamber. For example, U.S. Pat. No. 2,619,876 to Olson discloses a “magazine rifle” with an internal magazine.
Other rifles, such as the AR-15 semi-automatic rifle, use detachable magazines instead to feed cartridges. Those magazines are slid upwardly into well openings of receivers and removably latched in place.
Detachable magazines usually are elongated containers, generally rectangular in cross-section, which are attached to the underside of the rifle (i.e., inside a well opening of the receiver). Such magazines are commonly made of aluminum alloys, plastic, steel, or a combination.
Detachable magazines are usually closed on four sides (except for latch holes), closed on the bottom, and open on an upwardly facing top. The open top has a rectangular opening and includes two retaining members, known as feed lips, which project into or partly close the opening from opposite sides. An internal spring urges a follower or lifter (i.e., a shaped piece of plastic or metal) toward the open side. The spring-loaded follower in turn urges the rounds as a group up against the lips. The lips act as a stop for the rounds so that they are not expelled from the magazine.
Rounds are stacked or oriented in the detachable magazine such that the longitudinal axes of the rounds are substantially parallel and perpendicular to the direction of travel of the spring and follower. Adjoining rounds are oriented side-by-side and in the same direction, i.e., the bullets of adjacent rounds are next to each other, as are the cases.
The rounds are usually stacked in the magazine, either in a single straight column or in a staggered (zigzag) column (also called double-stacked or high-capacity) fashion. Double-stacked magazines contain two side-by-side staggered columns offset by approximately half of the diameter of a round. The double-stacked magazines, being wider, have a higher round capacity compared to single-column magazines of the same overall length.
As the firearm cycles, cartridges are moved to the top of the magazine by a follower driven by spring compression to either a single feed position or side-by-side feed positions. In the double-stacked magazines, the position of the next top round is staggered to the left or right.
At the top of such magazines, the feed lips alternately retain the left and right top-most round, as the rounds are fed up and picked off. The top-most round is held in place by only one of the lips. Hereafter the term “magazine” will mean magazines where the lips alternately retain the top-most round.
Prior to use, a firearm magazine must be loaded, charged, or filled with rounds. When a magazine is being loaded, it is necessary to depress all previously loaded rounds to provide vacant space below the lips so an additional round can be inserted or loaded into this space. Each time another round is loaded the spring is further compressed, requiring more insertion force.
When a magazine is fully loaded, the spring is fully compressed and exerts maximum upward force against the follower and rounds towards the lips. Sometimes though a spring is weakened. That can hinder stripping the rounds.
Accordingly, it is a primary object of the present invention to provide a mechanical device to help strip a cartridge off a detachable double-stacked magazine.
It is another object to provide a cartridge stripping device, integrally attached to the breech bolt head, which cooperates with existing double-stacked magazines.
It is another object to provide a cartridge stripping device, commensurate with the above-listed objects, which is durable to use.